To solve your problem use following code:
Node node = new Node(new object[]{});
or
//to prefill cell values with null values
Node node = new Node(new object[flyGrid.Columns.Items.Count]);
instead of:
Node node = new Node();
The default(empty) constructor is used in conjuction with initialization code:
Node node = new Node();
node.Value = (new object[]{\"Name\", true, null};
if you'll try to set some cell value on node created with default constructor, node will set node.Value to the value of cell, as node with empty node.Value (non-array or null value).
By the way, the following construction:
Node node = new Node(new object[]{\"Name\", true, null});
is the more effective and fast than
Node node = new Node(new object[]{});
node[\"first\"] = \"Name\";
node[\"second\"] = true;
or
node[0] = \"Name\";
node[1] = true;
or
node[firstCol] = \"Name\";
node[secondCol] = true;